Telephone-exchange circuit



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' 0. W. Ross; 2 TELEPHONE EXCHANGE GIRGUIT.

No. 252,259. Patented Jan. 10,1882.

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TELEPHONE EXCHANGE CIRCUIT. No. 252.259. Patented Jan. 10,1882.

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i v UNITED STATES PATENT I OFFICE.

CHARLES W. ROSS, OF COLUMBUS, OHIO, ASSIGNOR TO THE WESTERN ELEC- TRICMANUFACTURING COMPANY, OF CHICAGO, ILLINOIS.

TELEPHONE-EXCHANGE CIRCUIT.

SPECIFICATION forming part of Letters Patent No. 252,259, dated January10, 1882.

Application filed September 24, 1881. (No model.)

To all whom it may concern: 7

Be it known that], CHARLES W. Ross, of Columbus, Ohio, have discovered acertain new anduseful Improvement in Circuits between Table-Operators ofa Telephone-Exchange, of which the following is a full,clear, concise,and exact description.

My invention relates to telephoneexchanges in which the individual linesare arranged in IO groups at the central office upon the severalswitch-boards, and when flexible conductingcords with pegs are used tomake the required connections. The operators are placed at tables orleaves in front of the switch-boards. The calls are sent in and answeredin theusual manner.

Prior to my invention trunk-lines were used connecting severalswitch-boards of one system. These lines always terminated in bolts orconnecting-strips fastened rigidly to the switchboards, and in order tomake a connection between a telephone-line and the trunkline one peg ofa set of conducting-cords was placed in the switch belonging to the lineand the other peg in the bolt or connecting-strip. Two connections werethus required at each board, or four connections in all, to complete thecircuit of two subscribers lines. The slack of the cords was taken up bymeans of 0 springs from above or by weights below the table. The springswere not wholly satisfactory on account of their uneven tension, and theweights below made it necessary, where long cords were required, toraise the platforms 5 of the operators to an inconvenient height.

My improvement consists in providing a suitable number of pairs or setsof cords and plugs, and so connecting'them that each set shall extend toall operators boards; and also 40 in the method of taking up the slackof the flexible conducting-cords from above.

The switches and annunciators of five dil'ferent subscribers lines areshown at each of the boards A and Aof Fig. 1. The lines are not shown,as they may be run from the subscribers stations and connected with thecentraloffice apparatus in an y well-known way. I usually group aboutfifty lines on each switchboard. The calls are received and answered bymeans of the usual listening-operators outfit, and clearing-outannunciators may be provided in the circuit of any two connected linesin the usual manner.

The switch and annunciator boards A and A and the operators tables BandB are the same as have been heretofore used. The switches 1 and 5 areconnected at board A in the usual manner. The sets ofcords and plugs a be (Z of are connected respectively to all operators boards.

Suppose operator at board A receives a call from subscriber 3, who asksfor subscriber 10 of board A. The operator at board A, as she insertsthe plug of set a in switch 3, tells operator at board A to connect seta with line 10, which she does, as shown at board A. The two subscriberslines are thus connected by a single connection at each board.

Each common setot' cords and plugs abedef must be connected with all theoperators boards, so that an operator at any given board may give theorder of a subscriber to the operator of another board by simplyindicating to her the set of cords to be used and the line of thesubscriber wanted.

To prevent confusion I reserve certain sets of plugs and cords at eachboard for making connectionswiththecalling-subscribers. Thus sets a b 0may be used by. operator attable B and sets at e f by the operator attable B for connecting with the lines of subscribers callin g forsubscribers connected with otherboards.

[ find this arrangement especially useful when there are a large numberof table-operators.

In Fig. 2 of the drawings I have shown spring-jacks and annunciatorsplaced on the switch-board in the usual manner, with the flexibleconducting-cords suspended from the ceiling by means of weights andpulleys. The plugs, when not in use, are thus held under the 0 leaf C,in convenient reach of the operator.

I have shown a set, g, of cords connecting the switches h and i; also,sets 7c 70, Z l, and m m, for connecting switches of one board withswitches of other boards. Fig. 3 is a dia- 5 gram showing theconnections of sets kl m with theleaves C C C of threedifl'erentswitchboards. The sets k k, 860., are used at the first boardfor makingconnections with switches of subscribers who have asked forcon neotion with too subscribers at the second or third board. Sets Z Z,&c., are used in like manner at the second board for connecting withswitches of subscribers calling for subscribers of the first or 5 thirdboard, and sets an m, 830., at the third board for making connectionwith lines at the first or second board. The method of disposing of theslack of the flexible condnctingeords is shown in Fig. 2.

The terminal plugs, when not in use, are in convenient reach of theoperator under the leaf. Each cord-passes up through the leaf over itsmovable pulley and down again to the top of the leaf, and is connectedfrom thence to the tops of the leaves at other switch-boards, or in anydirection desired. Each movable pulley is supported by a cord orropepassing over a fixed pulley. fastened to the ceiling. Suificient weightis attached to each supporting cord to hold the movable pulleys upagainst the tension of the conducting-cords, whichare thus always heldtaut. The tension of the cords will always be uniform, whether drawndown and connected with the switches or otherwise.

In Fig. 3, Sheet 3, I have shown afull-sized section of the well-knownautomatic cut-out or spring-jack with the plug inserted, so as toseparate the lever r from ground-contact s. The telephone-line t is thusconnected with the flexible cord at, as shown, Any other of thewell-known switches that will do the necessary work may be used upon theswitchboards.

When the lines are open at the switch-board ordinary connecting platesor bolts may be used.

I claim- 1. The combination of one or more sets of 0 conducting-cordsand plugs with the different switch-boards and connecting-wirespermanently connecting each set to all the boards,

whereby any given switch of one board may be connected directly with anygiven switch 45 of any other board.

2. The combination of a fixed pulley, a movable pulley, and asupporting-cord and weight with a flexible conducting-cord and aswitching device, as described, whereby telephonelines maybe connectedand disconnected, while the slack of the conducting-cord is taken upfrom above and auniform tension maintained, as and for the purposespecified.

3. The combination ofsets of cords and plugs with three or moreswitch-boards, a cord with a terminal plug of each set being at eachboard, and connecting-wires, one for each set, permanently connectingthe different sets respectively to all the switch-boards, whereby thecircuit of any line of one board may be united direct-ly with thecircuit of any given line of any other board through a portion of theconnecting-wire of an y given set, substantially as and for the purposespecified.

4. Two or more telephone switch-boards provided with automatic cut-outsor switches, in combination with a conducting-wire passing to theseveral boards, and flexible conductingeords, with pegs, connected tothe conductingwire, one at each board, whereby by making one connectionat each of the two boards any two lines, one connected at one board andthe other at the other board, may bedisconnected from the ground andconnected together.-

5. Two or more telephone switch-boardsprovided with line terminals orswitches, in combination with a conducting-wire passing to the severalboards, and flexible conducting-cords, with pegs, connected to theconducting-wire, one at each board, whereby by making one connection ateach of two boards any line of one board may be connected to any line ofthe other board.

CHARLES W. ROSS.

\Vitnes'ses:

WILLIAM S. GRANGER, CHAS. A. WARREN.

